Re: [PATCH v3 net-next 00/17] PTP support for the SJA1105 DSA driver

[Vladimir Oltean]

On Wed, 5 Jun 2019 at 20:45, Richard Cochran <richardcochran@xxxxxxxxx> wrote:
>
> On Wed, Jun 05, 2019 at 02:33:52PM +0300, Vladimir Oltean wrote:
> > In the meantime: Richard, do you have any objections to this patchset?
>
> I like the fact that you didn't have to change the dsa or ptp
> frameworks this time around.  I haven't taken a closer look than that
> yet.
>
> > I was wondering whether the path delay difference between E2E and P2P
> > rings any bell to you.
>
> Can it be that the switch applies corrections in HW?
>

Yes it can be. It was one of the first things I thought of.
Normally it updates the correction field with its own residence time
in 1-step L2 event messages (but I use 2 step).
It also has a bit called IGNORE2STF (ignore 2-step flag) by which it
updates the correction field in all L2 event messages (including sync,
thereby violating the spec for a switch, as far as I'm aware). But I'm
not setting it.
I also looked at egress frames with wireshark and the correction field is zero.

> Thanks,
> Richard

Thanks,
-Vladimir